6-amino-4-methyl-3,4-dihydro-2H-1,4-benzoxazin-3-one → HCID 59377423, compound

Tetra-tert-butyl ammonium bromide (6.77 g, 14.04 mmol) was added to a solution of 6-amino-4-methyl-4H-benzo[1,4]oxazin-3-one (2.5 g, 14.04 mmol) in methylene chloride (100 ml) and MeOH (50 ml). The mixture was stirred at room temperature for 20 minutes, then quenched with aqueous sodium bisulfite solution. The mixture was extracted with methylene chloride, and the combined organic extracts were dried over MgSO4, filtered, concentrated under reduced pressure and purified via column chromatography to give 1.30 g of 6-amino-7-bromo-4-methyl-4H-benzo[1,4]oxazin-3-one as a light yellow solid, 40%.